<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgpu - instance mesh</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="main.css">
	</head>
	<body>

		<div id="info">
			<a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> webgpu - instance mesh
		</div>

		<script type="importmap">
			{
				"imports": {
					"three": "../build/three.webgpu.js",
					"three/tsl": "../build/three.webgpu.js",
					"three/addons/": "./jsm/"
				}
			}
		</script>

		<script type="module">

			import * as THREE from 'three';
			import { mix, range, normalWorld, oscSine, timerLocal } from 'three/tsl';

			import Stats from 'three/addons/libs/stats.module.js';

			import { GUI } from 'three/addons/libs/lil-gui.module.min.js';

			let camera, scene, renderer, stats;

			let mesh;
			const amount = parseInt( window.location.search.slice( 1 ) ) || 10;
			const count = Math.pow( amount, 3 );
			const dummy = new THREE.Object3D();

			init();

			function init() {

				camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.1, 100 );
				camera.position.set( amount * 0.9, amount * 0.9, amount * 0.9 );
				camera.lookAt( 0, 0, 0 );

				scene = new THREE.Scene();

				const material = new THREE.MeshBasicMaterial();

				// random colors between instances from 0x000000 to 0xFFFFFF
				const randomColors = range( new THREE.Color( 0x000000 ), new THREE.Color( 0xFFFFFF ) );

				material.colorNode = mix( normalWorld, randomColors, oscSine( timerLocal( .1 ) ) );

				const loader = new THREE.BufferGeometryLoader();
				loader.load( 'models/json/suzanne_buffergeometry.json', function ( geometry ) {

					geometry.computeVertexNormals();
					geometry.scale( 0.5, 0.5, 0.5 );

					mesh = new THREE.InstancedMesh( geometry, material, count );
					mesh.instanceMatrix.setUsage( THREE.DynamicDrawUsage );

					scene.add( mesh );

					//

					const gui = new GUI();
					gui.add( mesh, 'count', 1, count );

				} );

				//

				renderer = new THREE.WebGPURenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.setAnimationLoop( animate );
				document.body.appendChild( renderer.domElement );

				//

				stats = new Stats();
				document.body.appendChild( stats.dom );

				//

				window.addEventListener( 'resize', onWindowResize );

			}

			function onWindowResize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			//

			function animate() {

				render();

				stats.update();

			}

			async function render() {

				if ( mesh ) {

					const time = Date.now() * 0.001;

					mesh.rotation.x = Math.sin( time / 4 );
					mesh.rotation.y = Math.sin( time / 2 );

					let i = 0;
					const offset = ( amount - 1 ) / 2;

					for ( let x = 0; x < amount; x ++ ) {

						for ( let y = 0; y < amount; y ++ ) {

							for ( let z = 0; z < amount; z ++ ) {

								dummy.position.set( offset - x, offset - y, offset - z );
								dummy.rotation.y = ( Math.sin( x / 4 + time ) + Math.sin( y / 4 + time ) + Math.sin( z / 4 + time ) );
								dummy.rotation.z = dummy.rotation.y * 2;

								dummy.updateMatrix();

								mesh.setMatrixAt( i ++, dummy.matrix );

							}

						}

					}

				}

				await renderer.render( scene, camera );

			}

		</script>

	</body>
</html>
